DP Chemistry (last assessment 2024)

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Question 17N.3.hl.TZ0.a.ii

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Date November 2017 Marks available [Maximum mark: 2] Reference code 17N.3.hl.TZ0.a.ii
Level hl Paper 3 Time zone TZ0
Command term Deduce Question number a.ii Adapted from N/A
a.ii.
[Maximum mark: 2]
17N.3.hl.TZ0.a.ii

Ibuprofen and paracetamol are mild analgesics. One of the IR spectra below belongs to ibuprofen and the other to paracetamol. The structures of both compounds are given in section 37 of the data booklet.

Deduce which spectrum belongs to paracetamol, giving two reasons for your choice. Use section 26 of the data booklet.

[2]

Markscheme

X (must be identified) AND

Any two of:

For X:

N–H «absorption» AND at 3300 – 3500 «cm–1» ✔

O–H «absorption» in phenol AND at 3200 – 3600 «cm–1» ✔

absence of OH «absorption» in carboxylic acid AND 2500 – 3000 «cm–1»

Accept any specific wavenumber in the range 3300–3380 «cm–1» for M1.

Accept any specific wavenumber in the range 3100–3200 «cm–1».

Award [1 max] if Y is incorrectly identified for paracetamol but if a correct reason/reasons is/are given for the bond absorption(s).

[Max 2 Marks]